1. Field of the Invention
The present invention relates to a method for forming an interlayer insulating film and, more particularly, to a method for forming an interlayer insulating film having a low dielectric constant, which is necessary for a highly-integrated semiconductor device.
2. Description of the Related Art
Progress in high integration of semiconductor devices in recent years has resulted in a narrower interval between wiring lines. As the narrowed interval between the wiring lines causes an increase in capacitance between the wiring lines, a need has been created for an interlayer insulating film which has a low dielectric constant.
More specifically, recent progress in high integration of an LSI device, has led to the wiring lines being micronized and multilayered which, in turn, has led to an increase in capacitance between the wiring lines. Such an increase in capacitance has caused a great reduction in operating speed. Thus, improvement in this regard has been strongly demanded. As one improvement measure, a method for reducing capacitance between the wiring lines has been studied. This method uses an interlayer insulating film which has a dielectric constant lower than that of SiO.sub.2 currently used for an interlayer insulating film.
Typical interlayer insulating films of low dielectric constants currently under study are 1 an SiOF film, and 2 an organic insulating film of a low dielectric constant. Description will now be made of these films.